Last night everything was normal on Twitter. Today, when I logged on to Twitter, I could only see a few tweets and no more. I waited a few hours and retried only to realize that older tweets are not loaded whereas the new tweets are loaded. This is the screenshot of where the tweets end in the page:

Now I can only see the tweets tweeted in the last 8 hours. I tried this on my mobile phone and on another PC, and the result is the same.

When I open the profile of someone whom I follow, their tweets are shown properly.

The API will only load some max number of the most recent tweets to populate your timeline. Depending on how many people you follow, that could mean a days' worth or mere hours' worth of tweets. Sorry.